JP6977416B2 - Image processing equipment, information processing equipment and programs - Google Patents

Description

The present invention relates to an image processing device, an information processing device and a program.

Patent Document 1 discloses an image processing apparatus capable of maintaining a hue even when the silver color component is increased or decreased by treating the hue data as an apparatus-independent color space.

Patent Document 2 describes a maximum amount determining means for determining the maximum value of the amount of metallic color material when reproducing the color of the color signal from a given color signal, and the higher the saturation of the color signal, the more. The adjusting means for adjusting the amount of the metallic color material to be reduced within the range of the maximum value or less determined by the maximum amount determining means with respect to the apparent color change due to the metallic color, and the color signal and the adjusting means. A color processing apparatus is disclosed, which comprises a color material amount determining means for determining a color material amount other than the metallic color from the adjusted metallic color material amount.

Japanese Patent No. 5915302 Japanese Patent No. 5920580

An object of the present invention is to display a target color image printed by the amount of a plurality of color materials including a glittering color material on a display device, using a colorimetric value from a single direction. It is an object of the present invention to provide an image processing device, an information processing device, and a program capable of improving the color reproducibility of a target color image to be displayed as compared with the case of calculating a display value for displaying.

[Image processing device]
The present invention according to claim 1 is obtained when the amount of a plurality of color materials including a glittering color material is measured from a plurality of directions on a target color image printed using the plurality of color materials. The first conversion means to convert to the colorimetric value of
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on a display device is provided .
The second conversion means is
It has a storage means for storing a color conversion model for a display device in which a combination of a color measurement direction and a display value of each color and a color measurement value actually measured on the display device are associated with each other.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted by the first conversion means and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means is
When the brightness value of the color measurement value in the specular reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the specular reflection direction is relatively larger than that of the color measurement values in other color measurement directions. Further having a weighting coefficient setting means for setting a coefficient,
It is an image processing apparatus that calculates a weighted average value of a color difference in each color measurement direction by using a weighting coefficient set by the weighting coefficient setting means.

The present invention according to claim 2 is obtained when the amount of a plurality of color materials including a glittering color material is measured from a plurality of directions on a target color image printed using the plurality of color materials. The first conversion means to convert to the colorimetric value of
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on a display device is provided .
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means said that the larger the brightness value of the color measurement value in the normal reflection direction, the higher the brightness of the obtained display value than the brightness of the color measurement value in the front direction. It is an image processing device that converts a plurality of color measurement values converted by the conversion means into display values for displaying the target color image on the display device.

According to the third aspect of the present invention, when the second conversion means has a brightness value of a colorimetric value in the normal reflection direction equal to or higher than a preset threshold value, the brightness of the displayed value obtained is in the front direction. A claim for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on a display device so as to be higher than the brightness of the color measurement values. 2. The image processing apparatus according to 2.

The present invention according to claim 4 is the image processing apparatus according to claim 1 or 3 , wherein the threshold value is a blank lightness value.

The present invention according to claim 5 further includes the color measurement value when the plurality of color measurement values are measured in the diffused light direction on the side closer to the incident direction of the irradiation light than the front direction. The image processing apparatus according to any one of 1 to 4.

In the present invention according to claim 6 , the first conversion means has a combination of a color measurement direction and a color material amount of each color material, and a color measurement value measured in an actual printing result by a printing apparatus. By using the associated color conversion model for the printing device, the target color image when the amount of the color material of the plurality of color materials including the glittering color material is printed using the plurality of color materials is printed in a plurality of directions. The image processing apparatus according to any one of claims 1 to 5 , which converts a plurality of color measurement values obtained when the color is measured from.

The present invention according to claim 7 is the case where the target color image printed using the plurality of color materials is irradiated with light from an oblique direction with the amount of the color material of the plurality of color materials including the glittering color material. The first to convert to a plurality of color measurement values including the color measurement value when the color is measured in the front direction, which is the normal direction of the target color image, and the color measurement value when the color is measured in the normal reflection direction with respect to the irradiation light. 1 conversion means and
The larger the brightness value of the color measurement value in the normal reflection direction, the greater the brightness of the obtained display value than the brightness of the color measurement value in the front direction. It is an image processing device provided with a second conversion means for converting a color measurement value into a display value for displaying the target color image on the display device.

The present invention according to claim 8 is the image processing apparatus according to any one of claims 1 to 7 , wherein the bright color material is a metallic luster color toner.

[Information processing device]
The present invention according to claim 9 is a display device for displaying an image based on an instructed display value, and a display device.
The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on the display device.
A display control means for controlling the display of the target color image on the display device based on the display value converted by the second conversion means is provided .
The second conversion means is
It has a storage means for storing a color conversion model for a display device in which a combination of a color measurement direction and a display value of each color and a color measurement value actually measured on the display device are associated with each other.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted by the first conversion means and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means is
When the brightness value of the color measurement value in the specular reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the specular reflection direction is relatively larger than that of the color measurement values in other color measurement directions. Further having a weighting coefficient setting means for setting a coefficient,
It is an information processing apparatus that calculates the weighted average value of the color difference in each color measurement direction by using the weighting coefficient set by the weighting coefficient setting means.
The present invention according to claim 10 includes a display device that displays an image based on an instructed display value, and a display device.
The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on the display device.
A display control means for controlling the display of the target color image on the display device based on the display value converted by the second conversion means is provided.
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means said that the larger the brightness value of the color measurement value in the normal reflection direction, the higher the brightness of the obtained display value than the brightness of the color measurement value in the front direction. It is an information processing apparatus that converts a plurality of color measurement values converted by the conversion means of 1 into display values for displaying the target color image on the display device.

[program]
The present invention according to claim 11 is a plurality obtained when the amount of a plurality of color materials including a glittering color material is measured from a plurality of directions on a target color image printed using the plurality of color materials. The first conversion step to convert to the colorimetric value of
When the computer is made to execute the second conversion step of converting the plurality of color measurement values converted in the first conversion step into display values for displaying the target color image on the display device .
In the second conversion step,
Store the color conversion model for the display device in which the combination of the color measurement direction and the display value of each color is associated with the color measurement value actually measured on the display device.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted in the first conversion step and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
In the second conversion step,
When the brightness value of the color measurement value in the normal reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the normal reflection direction becomes relatively larger than the color measurement value in other color measurement directions. It is a program that calculates the weighted average value of the color difference in each color measurement direction by using the weighting coefficient set by the weighting coefficient setting means for setting the coefficient.
The present invention according to claim 12 is obtained when the amount of a plurality of color materials including a glittering color material is measured from a plurality of directions on a target color image printed using the plurality of color materials. The first conversion step to convert to the colorimetric value of
When the computer is made to execute the second conversion step of converting the plurality of color measurement values converted in the first conversion step into display values for displaying the target color image on the display device.
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
In the second conversion step, the brightness of the color measurement value in the normal reflection direction is larger, the brightness of the obtained display value is higher than the brightness of the color measurement value in the front direction. It is a program that converts a plurality of color measurement values converted in the conversion step 1 into display values for displaying the target color image on a display device.

According to the first aspect of the present invention, when a target color image printed by the amount of a plurality of color materials including a glittering color material is displayed on a display device, a color measurement value from a single direction is obtained. It is possible to provide an image processing device capable of improving the color reproducibility of the displayed target color image as compared with the case of calculating the display value for displaying the target image using the above.

According to the second aspect of the present invention, when a target color image having high brightness in the normal reflection direction and strong brilliance is displayed on a display device, the overall impression of the displayed target color image is used as a color sample. It is possible to provide an image processing device that can be brought close to each other.

According to the third aspect of the present invention, when a target color image having high brightness in the normal reflection direction and strong brilliance is displayed on a display device, the overall impression of the displayed target color image is used as a color sample. It is possible to provide an image processing device that can be brought close to each other.

According to the fourth aspect of the present invention, when a target color image having a high brightness in which the brightness in the normal reflection direction is larger than the brightness of a blank sheet is displayed on the display device, the overall target color image to be displayed is displayed. It is possible to provide an image processing device capable of bringing an impression closer to a color sample.

According to the fifth aspect of the present invention, it is possible to provide an image processing device capable of bringing the overall impression of the target color image displayed on the display device closer to the color sample.

According to the present invention according to claim 6 , when displaying a target color image printed by the amount of color material of a plurality of color materials including a glittering color material on a display device, a color measurement value from a single direction is obtained. It is possible to provide an image processing device capable of improving the color reproducibility of the displayed target color image as compared with the case of calculating the display value for displaying the target image using the above.

According to the present invention according to claim 7, when a target color image having high brightness in the normal reflection direction and strong brilliance is displayed on a display device, the entire target color image to be displayed is displayed by a simple configuration. It is possible to provide an image processing device capable of bringing a good impression closer to a color sample.

According to the eighth aspect of the present invention, when displaying a target color image printed by the toner amount of a plurality of toners including a metallic glossy color toner on a display device, a colorimetric value from a single direction is used. It is possible to provide an image processing device capable of improving the color reproducibility of the displayed target color image as compared with the case of calculating the display value for displaying the target image.

According to the present invention according to claims 9 and 10, when displaying a target color image printed by the amount of a plurality of color materials including a glittering color material on a display device, measurement from a single direction is performed. It is possible to provide an information processing apparatus capable of improving the color reproducibility of the displayed target color image as compared with the case of calculating the display value for displaying the target image using the color value.

According to the present invention according to claims 11 and 12, when displaying a target color image printed by the amount of color material of a plurality of color materials including a glittering color material on a display device, measurement from a single direction is performed. It is possible to provide a program capable of improving the color reproducibility of the displayed target color image as compared with the case of calculating the display value for displaying the target image using the color value.

It is a figure which shows the system structure of the printing system of 1st Embodiment of this invention. It is a figure for demonstrating the structure in the main body part of an image forming apparatus 10. It is a block diagram which shows the hardware composition of the terminal apparatus 20 of 1st Embodiment of this invention. It is a block diagram which shows the functional structure of the terminal apparatus 20 of 1st Embodiment of this invention. It is a figure for demonstrating how the target color image based on a color sample is displayed on the display apparatus 43. It is a figure for demonstrating the state at the time of measuring the color of the image which changes the tint in the viewing direction like a color sample of a metallic color. It is a figure for demonstrating the detailed structure of the colorimetric value conversion unit 41 shown in FIG. It is a figure for demonstrating the method of making the color conversion model (printer model) stored in the color conversion model storage unit 62. It is a figure for demonstrating the detailed structure of the display value conversion unit 42 shown in FIG. It is a figure for demonstrating the method of making the color conversion model (monitor model) stored in the color conversion model storage unit 73. It is a figure for demonstrating a specific example of the calculation method of the weighted average value ΔE (WAVG) of a color difference. This is an example of a graph showing a setting example of the weighting coefficients w1, w2, and w3 in the weighting coefficient setting unit 71. It is a figure for showing the setting example of the weighting coefficients w1, w2, w3 shown in FIG. 12 by a table. It is a figure for demonstrating the reflection characteristic of a normal image which is not a metallic color. It is a figure for demonstrating the difference in the reflection characteristic between a normal image which is not metallic color and a color sample image of metallic color. It is a figure for demonstrating the problem in the case of calculating the RGB value based only on the color measurement value from the front direction (45 °) when displaying the color sample image of a metallic color on a display device. According to one embodiment of the present invention, when the RGB value is calculated based on the color measurement values in a plurality of color measurement directions such as the front direction (45 °), the specular reflection direction (15 °), and the diffused light direction (110 °). It is a figure which shows the image example. It is a figure for demonstrating the structure of the image processing apparatus 40a in the 2nd Embodiment of this invention. It is a figure for demonstrating the detailed structure of the display value conversion part 42a shown in FIG. It is a figure which shows the setting example of the weighting coefficient W in the weighting coefficient setting unit 74. It is a figure for demonstrating the case where the color measurement of the measurement target image 50 is performed by the color measurement direction of 5 angles.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a configuration of a printing system according to the first embodiment of the present invention.

As shown in FIG. 1, the printing system of the present embodiment has a configuration in which an image forming apparatus 10 and a terminal apparatus 20 which is an information processing apparatus are connected by a network.

As shown in FIG. 1, the image forming apparatus 10 of the present embodiment is a so-called production printer used for commercial printing, and has a function of executing high-quality and high-speed printing processing.

The structure inside the main body of the image forming apparatus 10 will be described with reference to FIG. The image forming apparatus 10 includes five image forming units 24 as shown in FIG. The five image forming units 24 are configured to form an image using toners of yellow (Y), magenta (M), cyan (C), black (K), and special colors, respectively.

The special color toner includes silver silver toner (Si), gold gold toner (G), transparent toner, white toner, and the like, and one toner is selected from these special color toners. It is possible to use it. FIG. 2 shows a case where silver toner (Si) is selected and set from these special color toners.

In the present embodiment, when an image is formed using metallic (metallic luster) toner having brilliant (glossy) properties such as silver toner and gold toner, the amount of toner (coloring material) of each color including the metallic toner is formed. The case of determining the amount) will be described, but in the following description, the case of forming an image using silver toner will be described.

Here, the toner amount means the amount of toner used per unit area on the recording medium, for example, the toner weight (g / m ² ), but in the following description, the unit area, for example, used per pixel. When the maximum value of the amount of toner of each color to be printed is 100%, the ratio of the amount of toner of each color used for printing is expressed by a value (toner coverage) expressed in%.

The image forming unit 24 has a photoconductor drum, a charging device that uniformly charges the surface of the photoconductor drum, a developing device that develops an electrostatic latent image formed on the photoconductor drum, and the like. An electrostatic latent image is formed on each of the photoconductor drums of the image forming unit 24 by the laser beam irradiated by the optical scanning device 26, and the image is formed by being developed by the toner of each color.

Then, the images of each color formed in the image forming unit 24 are further transferred onto the printing paper that has been transferred after being transferred to the intermediate transfer belt 22. Then, the toner image transferred onto the printing paper is fixed on the printing paper by heat and pressure by the fixing device 28.

In this way, by forming an image using CMYKSi toner containing Si toner having brilliance, an image whose color, brightness, etc. change depending on the viewing direction is formed.

However, there are cases where it is desired to confirm the tint of the formed image before forming the image with the CMYKSi toner. For example, there is a case where it is desired to simulate an image formed by using CMYKSi toner and display it on a monitor of an information processing device such as a terminal device 20.

However, in a display device such as a monitor, the color of each pixel is determined by a display value such as RGB, and the tint, brightness, and the like hardly change depending on the viewing direction.

Therefore, when an image displayed on a display device such as a monitor is printed by the image forming apparatus 10 using CMYKSi toner, the visual impression may be significantly different between the printed image and the image on the display device. ..

In particular, when the RGB values for displaying the image on the display device are converted and generated based on the color measurement values when the brilliant image is color-measured from a single direction, the RGB values are displayed on the display device. The color and brightness of an image can be brought close to the brightness and color when viewed from a single direction, but the brightness and color when viewed from another direction cannot be reproduced.

In particular, an image having brilliance has a high brightness when viewed from a specular reflection direction, so that the color and brightness of an image having such brilliance when viewed from a single direction is reproduced on a display device. If this is the case, the impression will be darker than the actual image.

Therefore, when the terminal device 20 of the present embodiment converts the CMYKSi value to be printed by the image forming device 10 into an RGB value and displays it on a display device such as a monitor, the impression of the displayed image is more actual. It realizes a process of improving the color reproducibility of the displayed image by bringing it closer to the image printed on the image.

Next, FIG. 3 shows a hardware configuration of the terminal device 20 of the present embodiment that executes such processing.

As shown in FIG. 3, the terminal device 20 is a communication interface that transmits and receives data to and from a CPU 11, a memory 12, a storage device 13 such as a hard disk drive (HDD), and an external device via a network. (IF) 14, a user interface (UI) device 15 including a touch panel or liquid crystal display and a keyboard. These components are connected to each other via a control bus 16.

The CPU 11 executes a predetermined process based on the control program stored in the memory 12 or the storage device 13 to control the operation of the terminal device 20. In the present embodiment, the CPU 11 has been described as reading and executing a control program stored in the memory 12 or the storage device 13, but the program is stored in a storage medium such as a CD-ROM and stored in the CPU 11. It is also possible to provide.

FIG. 4 is a block diagram showing a functional configuration of the terminal device 20 realized by executing the above control program.

As shown in FIG. 4, the terminal device 20 of the present embodiment includes an image processing device 40 and a display device 43. The image processing device 40 is composed of a colorimetric value conversion unit 41 and a display value conversion unit 42.

The display device 43 is a device for displaying an image based on an instructed RGB value.

The image processing device 40 converts the CMYKSi value (toner amount) acquired from the image forming device 10 into an RGB value and displays it on the display device 43.

For example, as shown in FIG. 5, the image processing apparatus 40 obtains a CMYKSi value for printing a spot color sample image from the image forming apparatus 10 and converts it into an RGB value, based on the color sample image. A process is performed so that the target color image is displayed on the display device 43.

As the spot color sample image, for example, various metallic color sample images provided by PANTONE (registered trademark) or the like are used.

The color measurement value conversion unit 41 measures the toner amount CMYKSi value of a plurality of toners including the silver toner Si which is a brilliant color material when the target color image printed using the plurality of toners is measured from a plurality of directions. Convert to multiple obtained colorimetric values.

Specifically, the color measurement value conversion unit 41 prints the input CMYKSi value based on the CMYKSi value, and prints the target color image from three color measurement directions (15 °, 45 °, 110 °). It is converted into three color measurement values L * a * b * (15 °), L * a * b * (45 °), and L * a * b * (110 °) obtained when the color is measured.

Then, the display value conversion unit 42 has three color measurement values L * a * b * (15 °), L * a * b * (45 °) converted by the color measurement value conversion unit 41. L * a * b * (110 °) is converted into an RGB value which is a display value for displaying a target color image on the display device 43.

The details of the color measurement direction in which the color measurement value is generated by the color measurement value conversion unit 41 will be described with reference to FIG.

FIG. 6 is a diagram for explaining a state when measuring an image in which the tint changes in the viewing direction, such as a metallic color sample.

FIG. 6 shows a state in which the measurement target image 50 is measured from three angles of color measurement directions (15 °, 45 °, 110). Specifically, when the irradiation light from the light source 52 is applied to the target target image 50 from an oblique 45 ° direction and the specular reflection direction is 0 ° (reference direction), 15 °, 45 °, 110 It is shown that the color is measured by the color measuring device 54 in the ° direction.

In FIG. 6, the 45 ° direction is the front direction (normal direction) of the image to be measured 50. Further, the 15 ° direction is a specular reflection direction for measuring the specular reflected light of the image to be measured 50. It should be noted that the reason why the normal reflection direction for measuring the color of the positively reflected light is not set to the 0 ° direction but is shifted by 15 ° is that the positively reflected light is directly incident on the color measuring device 54 if the color is measured in the 0 ° direction. This is because the color to be measured cannot be measured.

Then, in FIG. 6, the 110 ° direction is set as the diffused light direction for measuring the color of the diffused light from the image to be measured 50.

In the present embodiment, the color measurement value conversion unit 41 converts the input CMYKSi value into a color measurement value when the color is measured from three color measurement directions, but at least two directions, for example, the front surface. The present invention is similarly applicable even in the case of converting to a colorimetric value from the direction (45 °) and the specular reflection direction (15 °).

Next, the detailed configuration of the colorimetric value conversion unit 41 will be described with reference to FIG. 7.

As shown in FIG. 7, the color measurement value conversion unit 41 includes a multi-angle color measurement value calculation unit 61 and a color conversion model storage unit 62.

The color conversion model storage unit 62 has a color conversion model ((L *,) in which a combination of the color measurement direction and the toner amount of each color toner is associated with the color measurement value measured in the actual printing result by the printing apparatus. a *, b *) = g (C, M, Y, K, Si, θ)) is stored. This color conversion model is for simulating the printing result by the printing apparatus and is called a printer model (color conversion model for the printing apparatus).

The multi-angle color measurement value calculation unit 61 prints the toner amount CMYKSi of a plurality of toners including silver toner by using the color conversion model stored in the color conversion model storage unit 62 using the plurality of toners. Multiple color measurement values L * a * b * (15 °), L * a * b * (45 °), L * a obtained when the target color image is measured from three color measurement directions. Convert to * b * (110 °).

Next, a method of creating the color conversion model stored in the color conversion model storage unit 62 will be described with reference to FIG.

First, a color chart (patch) image is output according to various combinations of C, M, Y, K, and Si values. Then, the color is measured for each color chart in the color measurement directions (15 °, 45 °, 110 °) of three angles by the color measurement method as shown in FIG. As a result, color measurement values of L * a * b * (15 °), L * a * b * (45 °), and L * a * b * (110 °) can be obtained for each color chart. Become.

Then, based on these values, a color such that a color value (L *, a *, b *) can be obtained by inputting (C, M, Y, K, Si, θ (color measurement direction)). Create a transformation model.

Specifically, a plurality of (C) (C) are obtained by measuring the color reproduced in advance by combining various C, M, Y, K, Si, and θ values and acquiring the L * a * b * values. , M, Y, K, Si, θ) and (L *, a *, b *). By using this set, a functional relationship (L *, a *, b *) = g (C, M, Y, K, Si, θ) can be obtained, and this may be used as a color conversion model. By using this color conversion model, it is possible to obtain the predicted color value L * a * b * given the toner amount CMYKSi of each color and the color measurement direction θ. As the function used for this color conversion model, a general function as a color conversion model such as a multiple regression equation, a neural network, and interpolation using a direct lookup table can be used.

In this way, a color conversion model (printer model) represented by the function (L *, a *, b *) = g (C, M, Y, K, Si, θ) was created and created. The color conversion model is stored in the color conversion model storage unit 62.

Next, the detailed configuration of the display value conversion unit 42 shown in FIG. 4 will be described with reference to FIG.

As shown in FIG. 9, the display value conversion unit 42 includes a weighting coefficient setting unit 71, an RGB value calculation unit 72, and a color conversion model storage unit 73.

The color conversion model storage unit 73 is a color conversion model (L *) in which a combination of RGB values, which are display values of the color measurement direction and each color, and the color measurement values actually measured on the display device 43 are associated with each other. , A *, b *) = f (R, G, B, θ) is stored. This color conversion model is for simulating the display result by the display device and is called a monitor model (color conversion model for the display device).

Here, a method of creating a color conversion model stored in the color conversion model storage unit 73 will be described with reference to FIG. 10.

First, a color chart (patch) image with various combinations of R, G, and B values is displayed on the display device 43. Then, the displayed color charts are measured in the three angle measurement directions (15 °, 45 °, 110 °) by the color measurement method as shown in FIG. As a result, color measurement values of L * a * b * (15 °), L * a * b * (45 °), and L * a * b * (110 °) can be obtained for each color chart. Become.

When actually measuring the color of the image displayed on the monitor screen, the obtained color measurement value does not change much even if the color measurement direction changes. Therefore, for simplicity, L * a * b * (15 °) = L * a * b * (45 °) = L * a * b * (110 °) may be set.

Then, based on these values, a color conversion model is created so that the color values (L *, a *, b *) can be obtained by inputting (R, G, B, θ (color measurement direction)). do.

Specifically, a plurality of (R, G, B) (R, G, B) are obtained by measuring the color reproduced by combining various R, G, B, and θ values in advance and acquiring the L * a * b * values. , Θ) and (L *, a *, b *) are obtained. By using this set, a functional relationship (L *, a *, b *) = f (R, G, B, θ) can be obtained, and this may be used as a color conversion model. By using this color conversion model, it is possible to obtain the predicted color value L * a * b * when the RGB value which is the display value and the color measurement direction θ are given. As the function used for this color conversion model, a general function as a color conversion model such as a multiple regression equation, a neural network, and interpolation using a direct lookup table can be used.

In this way, a color conversion model (monitor model) represented by the function (L *, a *, b *) = f (R, G, B, θ) is created, and the created color conversion model is It is stored in the color conversion model storage unit 73.

The RGB value calculation unit 72 is obtained from the color measurement values in the three color measurement directions converted by the color measurement value conversion unit 41 and the color conversion model (monitor model) stored in the color conversion model storage unit 73. The weighted average (weighted average) value ΔE (WAVG) of each color difference with the color measurement value in each color measurement direction is calculated, and the RGB value is set so that the calculated weighted average value ΔE (WAVG) of the color difference is minimized. decide.

A specific example of a method for calculating the weighted average value ΔE (WAVG) of the color difference will be described with reference to FIG. As shown in FIG. 11, the weighted average value ΔE (WAVG) of the color difference in each color measurement direction = {w1 × ((L * a * b * (15 °) and f (R, G, B, 15 °)). Color difference) + w2 × (color difference between (L * a * b * (45 °) and f (R, G, B, 45 °)) + w3 × ((L * a * b * (110 °)) and f ( Color difference from R, G, B, 110 °))} / (w1 + w2 + w3) is used to calculate the weighted average value.

Here, w1, w2, and w3 are a weighting coefficient in the specular reflection direction (15 °), a weighting coefficient in the front direction (45 °), and a weighting coefficient in the diffused light emission direction (110 °), respectively, and the weighting coefficient is set. It is set by the unit 71.

For example, when the color difference in each color measurement direction is treated with the same weighting, w1 = w2 = w3 = 1 may be set as the weighting coefficient. In this case, the weighted average value ΔE (WAVG) of the color difference is a simple average value.

The color difference ΔE (PQ) between the color value P = (L ₁ *, a ₁ *, b ₁ *) and the color value Q = (L ₂ *, a ₂ *, b _{2 *) is calculated by the following formula.} Is calculated by.
ΔE (PQ) = ((L ₁ * -L ₂ *) ² + (a ₁ * -a ₂ *) ² + (b ₁ * -b ₂ *) ² ) ^1/2

As a specific method for calculating the RGB value at which the weighted average value ΔE (WAVG) of the color difference is minimized, the RGB value calculation unit 72 is a numerical solution method of a nonlinear equation such as the Simplex method or the Newton method. Can be used to apply the general method of solving the optimization problem.

Here, in the present embodiment, the color measurement values in the three color measurement directions are measured in the front direction, which is the normal direction of the target color image, when the target color image is irradiated with light from an oblique direction. The color measurement value L * a * b * (45 °) in the case, the color measurement value L * a * b * (15 °) when the color is measured in the direction of normal reflection with respect to the irradiation light, and the color measurement in the diffused light direction. The case where the colorimetric value is L * a * b * (110 °) is described.

Then, the weighting coefficient setting unit 71 is based on the brightness value (L *) of the color measurement value L * a * b * (15 °) in the normal reflection direction, and the color measurement value L * a in the color measurement direction in three directions. * The weighting coefficients w1, w2, and w3 used when calculating the weighted average value of b * (15 °, 45 °, 110 °) are set.

Specifically, the weighting coefficient setting unit 71 sets the normal reflection direction when the brightness value (L *) of the color measurement value L * a * b * (15 °) in the normal reflection direction is equal to or larger than a preset threshold value. Weighting coefficient such that the weighting of the color measurement value L * a * b * (15 °) is relatively larger than the color measurement value L * a * b * (45 °, 110 °) in other color measurement directions. Set w1, w2, and w3.

12 and 13 show examples of setting the weighting coefficients w1, w2, and w3 in the weighting coefficient setting unit 71.

In the graph of the setting example of the weighting coefficient shown in FIG. 12, the weighting coefficient w3 having the color measuring direction of 110 ° is specularly reflected without changing the weighting coefficients w1 and w2 having the color measuring direction of 15 ° and 45 °. A case is shown in which the brightness value L * (15 °) in the direction is set to decrease as the value increases.

Specifically, the weighting coefficients w1 and w2 are always 1 regardless of the brightness value L * (15 °) in the specular reflection direction, but the weighting coefficient w3 is the brightness value L * in the specular reflection direction (15 °). When 15 °) is 100 or less, it is 1, but between 100 and 140, it gradually decreases from 1 to 0, and when it is 140 or more, it becomes 0.

A table showing an example of setting the weighting coefficients w1, w2, and w3 shown in FIG. 12 is shown in FIG.

In FIGS. 12 and 13, a setting example in which the weighting coefficient w3 changes depending on the brightness value L * (15 °) in the specular reflection direction has been described, but the weighting coefficients w2 and w3 are not changed. It is also possible to set w1 to increase as the brightness value L * (15 °) in the specular reflection direction increases. In this case, the value of the weighting coefficient w1 is larger than 1, such as 1.1, 1.2, ....

That is, as the brightness value (L *) in the specular reflection direction increases, the weighting coefficient w1 of the color measurement value L * a * b * (15 °) in the specular reflection direction becomes the color measurement value L * in the other color measurement direction. The setting may be made so as to be relatively larger than the weighting coefficients w2 and w3 of a * b * (45 °, 110 °).

The RGB value calculation unit 72 calculates the weighted average value of the color difference in each color measurement direction using the weighting coefficients w1, w2, and w3 set by the weighting coefficient setting unit 71, and the calculated weighted average value is the minimum. The RGB value is determined so as to be.

Then, by setting the weighting coefficients w1, w2, and w3 as described above, the RGB value calculation unit 72 has the brightness value of the color measurement value L * a * b * (15 °) in the normal reflection direction. Color measurement value conversion so that the larger (L * (15 °)), the higher the brightness of the obtained RGB value than the brightness of the color measurement value L * a * b * (45 °) in the front direction. The color measurement values L * a * b * (15 °, 45 °, 110 °) in the three color measurement directions converted by the unit 41 are converted into RGB values for displaying the target color image on the display device 43. Convert.

Specifically, the RGB value calculation unit 72 determines that the brightness value (L * (15 °)) of the color measurement value L * a * b * (15 °) in the normal reflection direction is equal to or greater than a preset threshold value. The color measurement directions in the three directions converted by the color measurement value conversion unit 41 so that the brightness of the obtained RGB values is higher than the brightness of the color measurement value L * a * b * (45 °) in the front direction. The color measurement values L * a * b * (15 °, 45 °, 110 °) in the above are converted into RGB values for displaying the target color image on the display device 43.

In other words, the RGB value calculation unit 72 obtains RGB values as the brightness value (L * (15 °)) of the color measurement value L * a * b * (15 °) in the normal reflection direction increases. Three color measurement values L so that the lightness is larger than the lightness when the color measurement values L * a * b * (15 °, 45 °, 110 °) in the three color measurement directions are treated equally. * a * b * (15 °, 45 °, 110 °) is converted into RGB values for displaying the target color image on the display device 43.

That is, as the brightness value L * (15 °) in the normal reflection direction increases, the color measurement value L * a * b * (15 °) in the normal reflection direction has a larger brightness value than the color measurement values in other color measurement directions. ) Is increased so that the RGB value is calculated, so that the brightness value of the obtained RGB value also becomes larger as the brightness value L * (15 °) in the normal reflection direction increases.

In the example of setting the weighting coefficient shown in FIGS. 12 and 13, when the brightness value L * (15 °) in the specular reflection direction exceeds 100, the weighting coefficient w3 in the diffused light direction is set to be small. However, this lightness value (100) is set to a value in the vicinity of the lightness value of general blank paper (white paper). It is considered that this is because when the brightness value L * (15 °) in the specular reflection direction exceeds the brightness value of a blank sheet, a human feels a metallic luster. The brightness value (100) is preferably set to 90 to 96 or more, which is the brightness value of a blank sheet, and is preferably set to 100 <, which is the brightness value of the completely diffused surface. Further, the RGB calculation unit 72 changes the sizes of the weighting coefficients w1, w2, and w3 according to the size of the lightness value L * (15 °) in the specular reflection direction, using the lightness value of the blank sheet as a threshold value.

By performing such processing, for a target color image with a brightness larger than the brightness of a blank sheet, all the color measurement values are made equal (same weighting) by increasing the weighting of the color measurement values in the normal reflection direction. The reason why the brightness is brighter than the brightness obtained by handling is explained below.

First, the reflection characteristics of a normal image that is not a metallic color will be described with reference to FIG. The reflection characteristics of a normal image that is not a metallic color are as shown in FIG. 14, and the amount of light in the specular reflection direction is larger than that in the other direction, but the amount of diffused light in the direction other than the specular reflection direction is almost the same. You can see that they are the same. Therefore, in a normal color measuring method, the irradiation light from the light source 52 is applied to the measurement target image 50 in an oblique direction, and the color value in the front direction (45 °) is measured by the color measuring device 54.

Next, the difference in reflection characteristics between a normal image having no metallic color and a color sample image having a metallic color will be described with reference to FIG.

Due to the difference in reflection characteristics between the metallic color sample image and the normal image, the metallic color sample image has a higher specular reflection direction (15 °) and a diffused light direction (110 °) than the normal image. ) Is low in brightness.

Therefore, the brightness when the metallic color sample image is viewed from the specular reflection direction (15 °) is higher than the brightness of the normal image which is not the metallic color. However, the difference in brightness when viewed from the front direction (45 °) is not so large between the metallic color sample image and the normal image. That is, the difference in brightness between the lightness in the specular reflection direction (15 °) and the brightness in the front direction (45 °) of the metallic color sample image is larger than that in the case of the normal image.

When displaying a metallic color sample image generated for such a reason on a display device, there is a problem when the RGB value is calculated based only on the color measurement value from the front direction (45 °). This will be described with reference to FIG.

With reference to FIG. 16, it can be seen that the brightness when the actual color sample image is viewed increases in the front direction (45 °) and the specular reflection direction (15 °). In the gradations 1 to 3 having particularly high brightness, the brightness is significantly different between the front direction (45 °) and the specular reflection direction (15 °).

Then, when the target color image for reproducing the color sample image is displayed on the display device using only the color measurement value in the front direction (45 °), the brightness when viewed from the front direction (45 °). It is possible to reproduce an image close to, but it can be seen that it is darker than the brightness when viewed from the specular reflection direction (15 °).

In particular, in a display device such as a monitor, the color, brightness, etc. of the displayed image hardly change depending on the viewing direction, so that the color, brightness, etc. of the image displayed on the display device are almost unchanged when viewed from any direction. It will be the same.

Therefore, when the color sample image whose brightness changes depending on the viewing direction is compared with the target color image on the display device, the user is given the impression that the target color image on the display device has low brightness.

However, as shown in FIG. 17, in the present embodiment, not only the front direction (45 °) but also a plurality of measurements such as the front direction (45 °), the normal reflection direction (15 °), and the diffused light direction (110 °). By calculating the RGB value based on the color measurement value in the color direction, the brightness of the image of the calculated RGB value is higher than that in the case of using only the color measurement value in the front direction (45 °). Become.

As a result, the target color image displayed on the display device 43 based on the RGB values obtained by the conversion direction of the present embodiment has a closer impression to the user even when compared with the actual color sample image. Become.

In particular, in the conversion method of the present embodiment, when the brightness value L * (15 °) in the specular reflection direction is 100 or more (gradations 1 to 3), the weighting in the specular reflection direction (15 °) is further increased. As a result, the brightness of the calculated RGB value image becomes higher.

Then, for a target color image having a brightness larger than that of a blank sheet, the difference from the brightness in the normal reflection direction (15 °) tends to be larger than the brightness in the front direction (45 °), and the difference from the brightness in the front direction (45 °) tends to be larger. If the RGB value to be displayed on the display device 43 is calculated based only on the color measurement value, when the user compares the actual color sample image with the target color image displayed on the display device 43, There is a high possibility that the target color image displayed on the display device 43 has the impression that it is dark.

Therefore, for a target color image with a brightness larger than the brightness of a blank sheet, the RGB values are not calculated by simply treating multiple color measurement values with different color measurement directions equally, but the measurement in the normal reflection direction (15 °). The weighting of the color values is increased so that the RGB values are calculated so as to increase the brightness of the obtained image. As a result, the impression when the user compares the actual color sample image with the target color image displayed on the display device 43 becomes closer.

[Second Embodiment]
Next, the printing system of the second embodiment of the present invention will be described.

The printing system of the present embodiment has a configuration in which the image processing device 40 in the terminal device 20 is replaced with the image processing device 40a shown in FIG. 18 with respect to the printing system of the first embodiment described above. There is.

As shown in FIG. 18, the image processing device 40a includes a colorimetric value conversion unit 41a and a display value conversion unit 42a.

The color measurement value conversion unit 41a in the present embodiment is a color measurement value L * a obtained when the input CMYKSi value is measured by measuring the target color image printed based on the CMYKSi value from the normal reflection direction. It is converted into * b * (15 °) and the color measurement value L * a * b * (45 °) obtained when the color is measured from the front direction.

Further, in the display value conversion unit 42a, the larger the brightness value L * (15 °) of the color measurement value in the normal reflection direction, the greater the brightness of the obtained RGB value than the brightness of the color measurement value in the front direction. , The color measurement value L * a * b * (45 °) in the front direction converted by the color measurement value conversion unit 41a is converted into an RGB value for displaying a target color image on the display device 43.

Next, the detailed configuration of the display value conversion unit 42a shown in FIG. 18 will be described with reference to FIG.

As shown in FIG. 9, the display value conversion unit 42a includes a weighting coefficient setting unit 74, an L * a * b * → RGB conversion unit 75, and an RGB value correction unit 76.

In the weighting coefficient setting unit 74, when the brightness value (L * (15 °)) of the specular color measurement value is a preset threshold value, for example, 100 (brightness value of blank paper) or more, the value is more than 1. The weighting coefficient W is set so as to gradually decrease.

FIG. 20 shows an example of setting the weighting coefficient W in the weighting coefficient setting unit 74.

Referring to FIG. 20, the weighting coefficient W is 1 when the brightness value (L * (15 °)) in the specular reflection direction is 100 or less, which is the brightness value of a blank sheet, but gradually decreases when it exceeds 100. You can see that it is a value.

The L * a * b * → RGB conversion unit 75 converts the input front color measurement value L * a * b * (45 °) into RGB values (R ₁ , G ₁ , B ₁ ).

_{The RGB value correction unit 76 corrects the RGB values (R 1} , G ₁ , B ₁ ) from the L * a * b * → RGB conversion unit 75 by the weighting coefficient W set by the weighting coefficient setting unit 74. Specifically, the RGB value correction unit 76 corrects the RGB values (R ₁ , G ₁ , B ₁ ) by performing the following operations, and displays the target color image on the display device 43. Output as an RGB value.

R = R ₁ / W
G = G ₁ / W
B = B ₁ / W

The display value conversion unit 42a in the image processing device 40a of the present embodiment creates and stores a color conversion model (monitor model) like the display value conversion unit 42 in the first embodiment described above. It becomes unnecessary. Further, in the display value conversion unit 42a, the calculation for calculating the RGB value to be output to the display device 43 may be performed only by performing a simple division as shown above, so that the processing load is lightened. As a result, the display value conversion unit 42a in the present invention is realized with a simple configuration as compared with the display value conversion unit 42 in the first embodiment.

[Modification example]
In the above embodiment, the case where the colorimetric value is represented by the CIE L * a * b * color space, which is a color system including at least the brightness information, is described. * h It is also possible to use a color system represented by another color space as long as it is a color system that includes lightness information such as a color system.

Further, in the above embodiment, the amount of toner of each color including silver toner is measured in three angles of the specular reflection direction (15 °), the front direction (45 °), and the diffused light direction (110 °). Although the case of converting into a value and calculating the RGB value for displaying on the display device 43 has been described, the present invention is not limited to such a case. Convert the amount of toner of each color including silver toner into color measurement values in multi-angle color measurement directions such as 3 angles or more, 4 angles, 5 angles, etc., and calculate RGB values for display on the display device 43. It is also possible to have a different configuration. For example, the measurement target is based on five color measurement directions: specular reflection direction (15 °), specular reflection direction (25 °), front direction (45 °), diffused light direction (75 °), and diffused light direction (110 °). FIG. 21 shows a case where the color of the image 50 is measured.

Even if the color measurement values in the color measurement directions of the five angles obtained by the color measurement method as shown in FIG. 21 are used, the target color image is displayed on the display device 43 by the same method as described above. It is possible to calculate the RGB value for this purpose.

That is, the colorimetric value conversion unit 41 adds the input CMYKSi value to the colorimetric values in the normal reflection direction (15 °), the front direction (45 °), and the diffuse reflection direction (110 °) in the front direction (15 °). The color measurement value of the target color image when the color is measured in a direction (25 °) closer to the normal reflection direction (15 °) than 45 °), and between the front direction (45 °) and the irradiation direction by the light source 52. It may be converted into the color measurement value of the target color image when the color is measured in the diffused light direction ( 75 °) in. Then, the display conversion unit 42 may calculate the RGB values for displaying the target color image on the display device 43 by using the color measurement values in the plurality of color measurement directions.

Further, in the above embodiment, the case where it is applied to an image forming apparatus that prints using metallic (metal glossy color) toner such as silver toner and gold toner has been described, but the present invention is limited to this. The present invention is similarly applied to the case where printing is performed using a brilliant color material such as a pearl color material whose color tone differs depending on the viewing direction even if the color material is other than toner. Can be done.

Further, in the above embodiment, the case where the target color image printed by the multi-color toner CMYKSi containing the silver toner Si is simulated and displayed on the display device has been described, but the present invention is limited thereto. is not it. The same applies even when the image represented by the CMYKSi value is simulated and printed by a printer using only basic color toner such as CMYK toner.

In this case, instead of the display value conversion unit 42, a conversion that calculates a CMYK value based on the color measurement values L * a * b * (15 °, 45 °, 110 °) in a plurality of color measurement directions. It suffices to provide a part. Then, in this conversion unit, instead of the color conversion model as a monitor model, a printer model generated based on a printing device that prints based only on the basic color toner CMYK is used to measure colors in a plurality of color measurement directions. The process of converting the value into a CMYK value may be performed.

By converting the RGB value obtained by the display value conversion unit 42 into an L * a * b * value again and converting this L * a * b * value into a CMYK value, only the basic color toner is used. It is also possible to configure the printer to simulate the printing of the target color image represented by the CMYKSi value.

Further, the conversion processing contents of the color measurement conversion unit 41 and the display value conversion unit 42, or the color measurement conversion unit 41a and the display value conversion unit 42a described in the first and second embodiments are collectively described as the CMYKSi value. It is also possible to generate a look-up table with 5 inputs and 3 outputs, such as inputting and outputting RGB values.

10 Image forming device 11 CPU
12 Memory 13 Storage device 14 Communication interface (IF)
15 User interface (UI) device 16 Control bus 20 Terminal device 22 Intermediate transfer belt 24 Image formation unit 26 Optical scanning device 28 Fuser 40, 40a Image processing device 41, 41a Color measurement value conversion unit 42, 42a Display value conversion unit 43 Display device 50 Measurement target image 52 Light source 54 Color measuring device 61 Multi-angle color measurement value calculation unit 62 Color conversion model storage unit 71 Weighting coefficient setting unit 72 RGB value calculation unit 73 Color conversion model storage unit 74 Weighting coefficient setting unit 75 L * a * b * → RGB conversion unit 76 RGB value correction unit

Claims (12)

The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on a display device, and a second conversion means.
Equipped with
The second conversion means is
It has a storage means for storing a color conversion model for a display device in which a combination of a color measurement direction and a display value of each color and a color measurement value actually measured on the display device are associated with each other.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted by the first conversion means and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means is
When the brightness value of the color measurement value in the specular reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the specular reflection direction is relatively larger than that of the color measurement values in other color measurement directions. Further having a weighting coefficient setting means for setting a coefficient,
Using the weighting coefficient set by the weighting coefficient setting means, the weighted average value of the color difference in each color measurement direction is calculated.
Image processing device. The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on a display device, and a second conversion means.
Equipped with
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means said that the larger the brightness value of the color measurement value in the normal reflection direction, the higher the brightness of the obtained display value than the brightness of the color measurement value in the front direction. The plurality of color measurement values converted by the conversion means of 1 are converted into display values for displaying the target color image on the display device .
Image processing device. In the second conversion means, when the brightness value of the color measurement value in the specular reflection direction is equal to or higher than a preset threshold value, the brightness of the obtained display value is higher than the brightness of the color measurement value in the front direction. The plurality of color measurement values converted by the first conversion means are converted into display values for displaying the target color image on the display device.
The image processing apparatus according to claim 2. The image processing apparatus according to claim 1 or 3, wherein the threshold value is a blank lightness value. The image processing according to any one of claims 1 to 4 , further comprising the color measurement value when the plurality of color measurement values are measured in the diffused light direction on the side closer to the incident direction of the irradiation light than the front direction. Device. The first conversion means is a color conversion for a printing device in which a combination of a color measurement direction and a color material amount of each color material is associated with a color measurement value measured in an actual printing result by the printing device. By using the model, a plurality of colors obtained when the target color image when the amount of the color material of the plurality of color materials including the glittering color material is printed using the plurality of color materials is measured from a plurality of directions. The image processing apparatus according to any one of claims 1 to 5 , which is converted into a colorimetric value of. The amount of the color material of a plurality of color materials including the glittering color material is the normal direction of the target color image when the target color image printed using the plurality of color materials is irradiated with light from an oblique direction. A first conversion means for converting into a plurality of color measurement values including a color measurement value when the color is measured in the front direction and a color measurement value when the color is measured in the direction of normal reflection of the irradiation light.
The brightness of the colorimetric value in the normal reflection direction is larger, the brightness of the obtained display value is larger than the brightness of the colorimetric value in the front direction. A second conversion means for converting the colorimetric value into a display value for displaying the target color image on the display device, and
Image processing device equipped with. The image processing apparatus according to any one of claims 1 to 7 , wherein the bright color material is a metallic luster color toner. A display device that displays an image based on the indicated display value, and
The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on the display device.
A display control means for controlling the display of the target color image on the display device based on the display value converted by the second conversion means.
Equipped with
The second conversion means is
It has a storage means for storing a color conversion model for a display device in which a combination of a color measurement direction and a display value of each color and a color measurement value actually measured on the display device are associated with each other.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted by the first conversion means and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means is
When the brightness value of the color measurement value in the specular reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the specular reflection direction is relatively larger than that of the color measurement values in other color measurement directions. Further having a weighting coefficient setting means for setting a coefficient,
Using the weighting coefficient set by the weighting coefficient setting means, the weighted average value of the color difference in each color measurement direction is calculated.
Information processing device. A display device that displays an image based on the indicated display value, and
The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion means and
A second conversion means for converting a plurality of color measurement values converted by the first conversion means into display values for displaying the target color image on the display device.
A display control means for controlling the display of the target color image on the display device based on the display value converted by the second conversion means.
Equipped with
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
The second conversion means said that the larger the brightness value of the color measurement value in the normal reflection direction, the higher the brightness of the obtained display value than the brightness of the color measurement value in the front direction. The plurality of color measurement values converted by the conversion means of 1 are converted into display values for displaying the target color image on the display device.
Information processing device. The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion step and
A second conversion step of converting a plurality of color measurement values converted in the first conversion step into display values for displaying the target color image on a display device, and a second conversion step.
When you let your computer run
In the second conversion step,
Store the color conversion model for the display device in which the combination of the color measurement direction and the display value of each color is associated with the color measurement value actually measured on the display device.
The weighted average value of the color difference between the color measurement value in each color measurement direction converted in the first conversion step and the color measurement value in each color measurement direction obtained from the color conversion model for the display device is the minimum. Determine the display value so that
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
In the second conversion step,
When the brightness value of the color measurement value in the normal reflection direction is equal to or greater than a preset threshold value, the weighting of the color measurement value in the normal reflection direction is relatively larger than that of the color measurement values in other color measurement directions. Using the weighting coefficient set by the weighting coefficient setting means to set the coefficient, the weighted average value of the color difference in each color measurement direction is calculated.
program. The first method of converting the amount of color material of a plurality of color materials including a glittering color material into a plurality of color measurement values obtained when a target color image printed using the plurality of color materials is color-measured from a plurality of directions. Conversion step and
A second conversion step of converting a plurality of color measurement values converted in the first conversion step into display values for displaying the target color image on a display device, and a second conversion step.
When you let your computer run
When the plurality of color measurement values irradiate the target color image with light from an oblique direction, the color measurement values when the color is measured in the front direction, which is the normal direction of the target color image, and the positive with respect to the irradiation light. Including the color measurement value when the color is measured in the reflection direction,
In the second conversion step, the brightness of the color measurement value in the normal reflection direction is larger, the brightness of the obtained display value is higher than the brightness of the color measurement value in the front direction. The plurality of color measurement values converted in the conversion step 1 are converted into display values for displaying the target color image on the display device.
program.

Images